A 78-year-old man, who had stepped into a swimming pool of a club at Rabindra Sarobar after several months’ gap, died in the pool on Friday morning.

Pradip Kumar Dey, a resident of Dharmatala Road in Kasba, had suffered a stroke in October last year, son Prasanta Dey said. The cause of his death on Friday was yet to be ascertained.

“My father used to be a regular swimmer before the stroke.... Today, he went to the pool to resume swimming,” Prasanta Dey said.

The accident happened at Calcutta Sports Association around 9.10am.

Dey, a retired BSNLofficial, was standing inshallow water when he suddenly collapsed, said Soumitra Sarkar, a member ofthe Calcutta Sports Association.

“We have five to 10 trainers and lifeguards at anygiven point of time. They were there then (when Sarkar collapsed). But before anyone could understand what was happening, the elderlymember collapsed,” Sarkar said.

Dey was taken to Manipal Hospitals, Dhakuria, where he was declared dead.

A hospital official said the elderly man was “unresponsive” when he was taken to the hospital at 9.34am.

“He was declared dead on arrival. It is a medico-legal case. The body has been shifted to the police morgue,” said the hospital official.

Police said an unnatural death case has been started. The family did not lodge any police complaint till Friday night.